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ROVER EGRESS DESIGNPROGRESS REPORT9/26/2011

Anton GalkinZack MorrisonHahna Alexander

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Progress Report

Semester Schedule Research of Design Constraints Initial Design Concepts Comparison of Designs Selected Design Path Test Plan

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Semester Schedule

Presentations

Research

CAD Work

Model Validation

Cost Estimate

Order Parts

Fabrication

Testing

Lander Integration

Final Report Due

Research

CAD Work

Model Validation

Cost Estimate

Order Parts

Fabrication

Testing

Lander Integration

Final Report Due

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Research: Launch Dynamics

Static Loads: +6G/–2G axial ±2G lateral

Dynamic loads: MIN: 20G at 100Hz MAX: 3000G at 2000Hz

Vibration: Fundamental vibration modes do

not couple with Falcon 9 rocket Precision components held in

place by friction can become misaligned

Center of Gravity Lateral Offset: MAX 0.5in spin-stabilized mission MAX 5.0in non-spin stabilized

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Research: Vacuum Space FlightThermal regulation through radiation only

High voltage charge can accumulate on spacecraft Voltage potential over non-conducting (e.g.

composite) surfaces Uncontrolled discharge can damage spacecraft

Ultraviolet radiation detrimental to many materials Polymer erosion & out-gassing can contaminate

spacecraft Stripping of oxidation layer can cause cold welding

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Temperature Variation

-1 0 1 2 3 4 5 6 7

-150

-100

-50

0

50

100

150

200

250

300

Pre-Launch: 70°F

Launch: 200°F Space: -100°F

to +170°F

Lunar Day: 176°F to

253°F

Time (Days)

Temp (°F)

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Material Selection

Aluminum Titanium Composite (carbon fiber & aluminum

honeycomb)

0

50

100

150

200

250

300

350

400

450

237

22

100

300

Thermal Conduc-tivity (k, W/m°K)

Alum

inum

Tita

nium

Compo

site

0

5

10

15

20

25

23

8

2

20

Thermal Ex-pansion

(αv x10-6K-1)

Aluminum Titanium Composite0

0.050.1

0.150.2

0.250.3

0.350.4

0.450.5

0.04

0.13

0.45

0.03

Emissivity (ε) & Absorp-tivity (α)

?

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Design Concepts

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Design Concepts

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Design Concepts

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Design Concepts

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Design Concepts

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Design Comparison Chart

1. Dual Direction Ramp2. Segmented Ramp

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Comparison to Segmented Design

Tele

scopin

g R

am

p

Dual D

irect

ion R

am

p

Roll-u

p

Rope L

adder

Tensi

on A

ssem

bly

Show

er

Curt

ain

Ram

p C

hute

Sci

ssor

Arm

Rota

ting A

rm

-40

-35

-30

-25

-20

-15

-10

-5

0

5

Rati

ng

Com

pare

d t

o

Seg

men

ted

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Test Plan – Deployment

Deployment Reliability

Successful Deployment

Landing Accuracy

Deployment Time

Geometric Constraints

Deployment Angle

Stress/Deflection

Component Failure

Impact Force

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Test Plan – Egress

Egress Reliability Egress Success

Stress/Deflection

Joint Failure

Wheel-Ramp Interaction

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Test Plan – Landing Conditions Lander Tilt – Deployment Reliability

Lunar Terrain – Deployment, Egress Reliability Worst Case 30cm Rocks/Holes

Ground-Hole Ground-Rock Rock-Rock Hole-Hole Rock-Hole

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Questions?